On 03/03/2017 06:51 AM, Bernd Schmidt wrote:
This is an ICE where setup_pressure_classes fails if xmm0 is a global reg. Instead of GENERAL/FLOAT/SSE/MMX_REGS, it computes only SSE_FIRST_REG as the third register class. The problem is that the costs for moving between SSE_FIRST_REG and SSE_REGS are inflated because we think we have no available registers in SSE_FIRST_REG (since the only register in that class is global), and that somewhat confuses the algorithm.The following fixes it by tweaking contains_regs_of_mode. Out of caution, I've retained the old meaning for code in reload which uses this. Bootstrapped and tested on x86_64-linux. Ok? Bernd global-reg-cost.diff PR rtl-optimization/79728 * regs.h (struct target_regs): New field x_contains_allocatable_regs_of_mode. (contains_allocatable_regs_of_mode): New macro. * reginfo.c (init_reg_sets_1): Initialize it, and change contains_reg_of_mode so it includes global regs as well. * reload.c (push_reload): Use contains_allocatable_regs_of_mode rather thanc ontains_regs_of_mode. PR rtl-optimization/79728 * gcc.target/i386/sse-globalreg.c: New test.
And I went ahead and installed on the trunk. jeff
